In the past, in a drum washing machine, a transverse-shaft type drum is rotated in an outer drum which stores water at a bottom, washings are lifted up and dropped down by baffles arranged in the drum, and the washings are thrown to an inner circumferential surface of the drum to realize washing. In such a configuration in which the washings are stirred by the baffles, it is difficult for the washings to intertwine with each other or rub against each other. Therefore, with respect to the drum washing machine, in order to improve the cleaning performance, the following structure can be adopted: a stirring body is arranged on a rear surface of the drum, so that the drum and the stirring body can independently rotate at different rotating speeds during washing and rinsing.
During dewatering of the drum washing machine, the drum and the stirring body integrally rotate at the same rotating speed. Therefore, a clutch mechanism part for switching a driving mode between a first mode in which the drum and the stirring body independently rotate and a second mode in which the drum and the stirring body integrally rotate is arranged.
The drum and the stirring body are rotationally driven by a driving motor. A rotating shaft of the drum is connected with a planetary carrier of a planetary gear mechanism, and the rotation of the driving motor is transferred to the drum by virtue of the planetary gear mechanism. The clutch mechanism part includes a clutch body and a moving mechanism part. The clutch body is connected with an internal gear that forms the planetary gear mechanism in a manner that the clutch body cannot rotate relative to the internal gear. The moving mechanism part enables the clutch body to move between a driving motor side and a bearing unit side of the rotating shaft supporting the drum freely and rotationally. Splines are formed on the clutch body, at the rotor side end and at the bearing unit side end along a circumferential direction, and splines corresponding to the spline on the clutch body are formed on the rotor and the bearing unit.
The splines of the clutch body are engaged with the splines of the bearing unit in the first mode. Thus, the internal gear is fixed to the bearing unit by virtue of the clutch body in a manner that the internal gear cannot circumferentially rotate. When the rotor rotates in the state, the drum rotates independently of the stirring body at a rotating speed lower than that of the stirring body according to a reduction ratio of the planetary gear mechanism. In another aspect, the splines of the clutch body are engaged with the splines of the rotor in the second mode. Thus, the internal gear is fixed to the rotor by virtue of the clutch body. The drum integrally rotates with the stirring body at a rotating speed equal to that of the stirring body when the rotor rotates in this state.
The following condition may occur in the above drum washing machine: when the clutch body moves to the bearing unit side through the moving mechanism part, teeth of the splines of the clutch body and teeth of the splines of the bearing unit are abutted with each other rather than engaged. In this state, the clutch body is continuously pushed to the bearing unit side by the moving mechanism part. In this state, when the clutch body rotates through the internal gear along with the rotation of the rotor and a position of the tooth of the spline of the clutch body is shifted to a position not affected by the tooth of the spline of the bearing unit, the clutch body suddenly moves to the bearing unit side, so that the teeth of the splines are mutually engaged. However, impact sound which is harsh for a user may be generated between the clutch body and the bearing unit.
Similarly, when the clutch body moves to the rotor side through the moving mechanism part, teeth of the splines may also be abutted with each other rather than engaged. In this state, the clutch body is continuously pushed to the rotor side by the moving mechanism part. In this state, when a position of the tooth of the spline of the rotor is shifted to a position not affected by the tooth of the spline of the clutch body along with the rotation of the rotor, the clutch body suddenly moves to the rotor side, so that the teeth of the splines are mutually engaged. However, impact sound which is harsh for a user may be generated between the clutch body and the rotor.